Wizards of the Coast is looking to start their 1.0 launch of Magic: Arena off right, and part of that initiative involves a new event that's straight to the point in terms of its nomenclature: "Win Every Card Challenge."
Seeped in standard (currently, the only way truly play Arena until historic arrives), the event allows you to use every card currently in the game (again, in standard) to build any possible deck. From there you'll duke it out with other players in a one time tournament fashion up to 12 wins and two losses: if you lose, you're out of the family event forever. There's no takebacks or redos, you get the reward tier (below) and that's it.
The event will run from October 5 at 8PM PT through October 7 at 8AM PT, so Saturday night through Monday morning. It'll be a best of one format as is customary with Arena (paper Magic is typically best of three), so bring your A-game. The most notably rewards are one copy of every card in the newest set, Throne of Eldraine for 11 wins, and one copy of every card in standard (Guilds of Ravnica, Ravnica Allegiance, War of the Spark, M20, Throne of Eldraine) for 12 wins.
I don't suspect a lot of people will get that 12-win reward but it's there, and even zero wins will net you a sleeve and a card, so you may as well participate! Although you can swap decks between matches (and thus, losses), I think I'll be bringing my Simic Flash deck, as I've been having a ton of fun with it lately now that Brazen Borrower and Once Upon a Time are in the mix.
State of the Game [Wizards of the Coast]